this idiot forgot to commit an entire month's worth of code

Assets/Scripts/ShopManager.cs

@@ -0,0 +1,58 @@
+using System.Collections.Generic;
+using UnityEngine;
+
+public class ShopManager : MonoBehaviour
+{
+    #region Statication
+
+    public static ShopManager instance;
+
+    private void Awake()
+    {
+        if (instance != null && instance != this)
+        {
+            Destroy(gameObject);
+            return;
+        }
+        instance = this;
+        DontDestroyOnLoad(this);
+    }
+
+    #endregion
+    public List<AbilityUpgrade> buyableUpgrades;
+    public int currency; //uh. we need to figure out this one lol
+    public GameObject shopUIObject;
+    [SerializeField] private Marisa player;
+    public void GenerateUpgradeList()
+    {
+        
+    }
+
+    public void BuyUpgrade(AbilityUpgrade abilityToBuy)
+    {
+        if (currency >= abilityToBuy.cost)
+        {
+            AbilityManager.instance.upgradesInventory[abilityToBuy]++;
+            currency -= abilityToBuy.cost;
+        }
+
+    }
+
+    public void SellUpgrade(AbilityUpgrade abilityToSell)
+    {
+        AbilityManager.instance.upgradesInventory[abilityToSell]--;
+        currency += abilityToSell.cost/2;
+    }
+
+    public void OpenShopUI()
+    {
+        shopUIObject.SetActive(true);
+        player.stalled = true;
+    }
+
+    public void CloseShopUI()
+    {
+        shopUIObject.SetActive(false);
+        player.stalled = false;
+    }
+}